1. Field of the Invention
The present invention relates to a vehicle headlamp and more particularly to a vehicle headlamp that has a cap-shaped shade covering the light bulb.
2. Prior Art
In a vehicle headlamp, in order to block the light directed forward from the light bulb and the light which is difficult to control and becomes glare light, a cap-shaped shade is employed. The cap-shaped shade is provided so as to cover the front end portion of the light bulb.
As well known, the light bulb used in a vehicle headlamp becomes considerably high temperature when it is lit. The heat generated when the lamp is on is normally released by convection, radiation and the like. However, when the cap-shaped shade is used and the front end portion of the bulb is covered by shade, the heat tends to remain in an area covered by the shade, and the stored heat increases the temperature of the bulb even further. When the temperature of the light bulb becomes too high, the life of the bulb is shortened.
Accordingly, it is an object of the present invention to provide a vehicle headlamp that secures a ventilation between an area covered by the cap-shaped shade inside the reflector and the outside of the reflector, thus preventing the heat from being trapped in the area covered by the cap-shaped shade.
The above object is accomplished by a unique structure of the present for a vehicle headlamp that comprises: a lamp body which has a concave portion with its front face opened, a front cover which covers the front opening of the lamp body, a reflector which is tiltably installed in the lamp body, a bulb which is supported by the reflector, and a cap-shaped shade which blocks the light emitted directly from the bulb so that the bulb light is not directly irradiated at least forward; and in the present invention, the reflector has an air ventilation hole which is formed in an area that is on a peripheral edge of a bulb mounting portion of the reflector and is on an inner side, when viewed from the front, of the outer edge of the shade.
With this structure, heat inside the cap-shaped shade is released to the outside of the reflector through the air ventilation hole which is formed so as to correspond to the inside area of the cap-shaped shade. Heat is thus not trapped inside the cap-shaped shade, the temperature of the bulb is prevented from becoming too high (or higher than required), and the life of the bulb is not shortened by the heat inside the cap-shaped shade.